Finasteride, a synthetic 4-azasteroid compound. 4-azaandrost-1-ene-17-carboxamide, N-(1,1-dimethylethyl)-3-oxo-(5a 17B)-, sold under the trade name Proscar, as identified by U.S. Pat. No. 5,175,155, the entire disclosure is incorporated by reference herein, is known for use in treatment of benign prostatic hypertrophy (BPH). Said U.S. Pat. No. 5, 175,155 discloses the combination of finasteride and another agent, but preferably in the present invention finasteride is the only active ingredient, although combinations with other active ingredients are contemplated.